Forward poppet thermostat

ABSTRACT

A thermostatic valve to be mounted in the coolant system of an internal combustion engine to control the flow of fluid through the system. A thermostatic valve of the forward poppet-type in which a single poppet cooperating with a single valve seating surface is independently responsive to both temperature and pressure for controlling the flow of fluid through said valve. The poppet is slidably engaged with the extending thermal element and spring biased into a seated or closed position. The poppet will unseat, or open, in response to an extension of the thermal element or, totally independently of the thermal element, will unseat in response to an upstream pressure sufficient to overcome the spring bias.

D United States Patent [151 3,64%,454 Flreismuth et al. Feb. 8, 1972[54] FORWARD POPPET THERMOSTAT 3,485,448 12/ 1969 Coudriet ..236/34 [72]Inventors: John Bismuth, Arlington Heights, 1'; 3,558,046 l/l97l KellyNello L. Benedetfi, deceased, late of Mt.

Prospect, L, by Lena Benedetti, Exec- 57 fi z gr g Mlchael utor, MountProspect, lll. tomey eagno y [73] Assignee: Yale & TOWHE fine, by saidlFl'Q- 57 ABSTRACT [22] Filed; Jun), 24 1970 A thermostatic valve to bemounted in the coolant system of an internal combustion engine tocontrol the flow of fluid p 53,007 through the system. A thermostaticvalve of the forward poppet-type in which a single poppet cooperatingwith a single [52] US. Cl 236/34 valve Seating surface is independentlyresponsive to both term [5| Int. Cl. ..Folp 7/ 16 pet-3mm and pressurefor controlling the flow of fluid through [58] Field 0 34.5, 93 valve'The p pp is g g h extending thermal element and spring biased into aseated or closed posi- [56] Referem Cited tion. The poppet will unseat,or open, in response to an exten- UNITED STATES PATENTS sion of thethermal element or, totally independently of the thermal element, willunseat in response to an upstream pres- 21;: grapeau ure sufi'icient toovercome the pring rapeau 3,353,745 1 1/1967 Beatenbough ..236/34 3Claims, 3 Drawing Figures '2 a 4 o I 3 Q 42 5| 1. u I l PATENTEDFEH "8m2 3; 640,454

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JOHN s. FREISMUTH IVELLO L. BEA/05777 A TTORNEYS FORWARD POPPETTHERMOSTAT BACKGROUND OF THE INVENTION This invention relates toimproved thermostatic valves for internal combustion engine coolingsystems, and more particularly to thermostatic valves of the singleforward poppet type which will open, independent of any temperaturerise, in response to a predetermined upstream pressure.

Heretofore, single poppet valves used to control the temperature ofcoolant in internal combustion'engines were controlled by thermalelements which operated to open the poppet valves as the temperature ofthe coolant reached a predetermined value. The response of the valve tothe excessive pressures generated by the water pump during fast startupof a cold engine, if any, was a result of the fluid pressureoverpowering the thermal element and forcing the poppet into a forwardor open position. Such overpowering of the thermal element isundesirable as it occurs at different pressure levels for differentvalues of coolant temperature making a predictable pressure reliefdifficult or impossible. Such an overpowering may also have a damagingeffect on the thermal element. Attempts to provide for an accuratepressure relief in a thermostatic valve of the type described haveincluded the utilization of at least two separate valving ports, onethermostatically controlled and the other pressure controlled within thesame thermostat. This approach is undesirable as its requires a morecomplicated and expensive valve structure.

A principal object of this invention, therefore, is to provide animproved thermostatic valve.

A further object of the invention is to provide an improved forwardpoppet valve in which a single poppet is independently responsive toboth temperature and pressure.

A further object of the invention is to provide an improved thermostaticvalve of the forward poppet type in which a single poppet cooperatingwith a single valve seating surface provides a pressure relief inaddition to its thermal responsive function.

A further object of the invention is to provide an improved thermostaticvalve of the single forward poppet type in which the poppet is springbiased into a closed position and is slidably engaged to the thermalunit and thus, by careful selection of the thermal unit and biasingspring, will open in response to either a predetermined temperature or apredetermined pressure.

SUMMARY OF THE INVENTION This invention relates to an improvedthermostatic valve of the forward poppet type for use in the coolantsystem of an internal combustion engine. The valve is independentlyresponsive to both temperature and upstream pressure as will beexplained below. The valve body is located in the coolant conduit andhas a valve seat defining a flow port and a poppet valve for regulatingthe fluid flow therethrough. The poppet is spring biased to seat on thelow pressure, or upstream side of the valve seat and cooperates with theseat to control the flow of fluid. A thermal element is mounted on thehigh pressure, or upstream side of the valve body and has a power memberfor thermally activating the poppet extending in a downstream directiontherefrom. The power member is further extensible in the downstreamdirection in response to predetermined temperatures. The poppet isslidably engaged to the power member and will unseat from said valveseat in response to downstream extensions of said power member. At apredetermined upstream pressure sufiicient to overcome the bias, thepoppet will slidably disengage from the power member and move upstreamto unseat totally independently of said power member, thus providing asingle forward poppet valve independently responsive to both temperatureand downstream pressure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of thethermostat of this invention within a cooling system.

FIG. 2 is a sectional view of the thermostat illustrating the inventionsthermal mode of operation.

FIG. 3 is a sectional view of the thermostat illustrating the inventionspressure responsive mode of operation.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 illustrates a thermostat 10mounted in an internal combustion engine coolant conduit system showngenerally at 11. The thermostat 10 is generally interposed between theupstream high pressure area 11 and the downstream low pressure area 11"of coolant system 11. The thermostat l illustrated in the drawingscomprises a generally transverse wallpiece 12 which has an annularflange 13 extending therefrom which provides a means for mounting thethermostat in a desired location in the cooling system of an internalcombustion engine or the like. The transverse wallpiece 12 also has aninwardly and upwardly extending portion 14 which is apertured as at 15to define a valve seating surface and flow port for the flow of coolantthrough the thermostat.

A strut 16 extends upwardly from the transverse wallpiece 12 and isrigidly connected thereto at 17 by welding or the like. The strut 16 hasan inwardly and downwardly extending portion 18 which is apertured as at19 to form an annular guiding member. The uppermost portion 20 of strutI6 is concave in a generally downward direction whereat compressionspring 50 engages the undersurface of strut portion 20.

The thermal element is of the well-known solid-filled" type andcomprises a temperature sensitive portion 31, a collar 32, a powermember guide portion 33, and a power member 34. The thermostat containsa fusible thermally expandable material within the temperature sensitiveportion 31 which begins expanding when the ambient temperature rises toor above the critical temperature of the expandable material andcontinues to expand at a predetermined rate thereafter. The expandablematerial includes a diaphragm within the power unit which in turn abutsor is connected to the power member 34 so that the heating of thetemperature sensitive portion 31 above the critical temperature theexpandable material contained therein will affect relative extensiblemovement of the power member 34 from the casing of the power unit. Forthe purposes of simplicity, that portion of the power unit 30 whichincludes a temperature sensitive portion 31, a collar 32, and a guideportion 33 is referred to as the easing. Downwardly extending bracket 35mounts the casing to the transverse wallpiece 12.

It will be noted that while the casing is mounted by bracket 35 to thetransverse wallpiece 12, power member 34 is free to move. Therefore, atambient temperatures at or above the critical temperature of theexpandable material contained within the temperature sensitive portion31 of the thermal sensitive power unit 30 power member 34 will expand ina generally downstream direction.

Poppet valve member is formed with a generally discshaped portion 41which cooperates at upwardly flared portion 41' with valve seat [5 tocontrol the flow of fluid through the flow port. Upwardly flared portion41' of disc 41 assures proper seating of poppet 40 upon valve seat 15.Poppet 40 also has a centrally located, upwardly extending, elongatedcup-shaped portion 42 with a cap 43 thereon.

It will be noted that the exterior of cup-shaped portion 42 is slidablyengaged and guided by guide portion 19 of strut l6. It will also benoted that the interior of cup-shaped portion 42 is slidably engagedwith power member 34.

The compression spring is mounted between concave portion 20 of strut 16and the upper surface of poppet discshaped portion 41. The spring 50contacts the poppet discshaped portion at 51 to bias the poppet intoseated position on the valve seating surface 15 of wallpiece 12. Whenpoppet 40 engages the valve seat 15 as shown in FIG. I, the coolantfluid will not flow from high pressure area 11' through the flow port tolow pressure area 11''.

In operation, the thermostat is independently responsive to bothupstream temperature and upstream pressure as will be described below.

If the temperature of the coolant within the engine block is initiallyquite cold and it is therefore below the critical temperature of theexpandable material within temperature sensitive portion 31 the powermember 34 will not expand and the poppet valve 40 will remain seated onvalve seat thus blocking the flow of fluid through valve 10. As thetemperature of the coolant rises to equal or exceed the criticaltemperature, power member 34 will expand upwardly engaging cap 43 ofpoppet valve 40, the power member will thus carry poppet valve 40 in anupward direction against the bias of spring 50 and unseat disc section41 from valve seat 15 allowing coolant to flow through the flow port ofthe thermostatically controlled valve 10. The thermal mode of operationof the thermostat 10 may be seen by reference to FIG. 2. Alternately,and totally independently of the thermal mode of operation is thepressure mode of operation. If a fluid pressure rise occurs on theupstream side 11' of disc 41 which is sufficient to overcome the biasingforce of spring 50 which is in turn maintaining poppet valve 40 inengagement with the valve seat 15, the poppet valve 40 willindependently move upward against the biasing force thereby opening theflow port of thermostatically controlled valve 10. This is possiblebecause poppet 40 is slidably disengageable from power member 34 in thedownstream, or low pressure, direction as is indicated in FIG. 3.

It should be noted that all upward and downward movement of poppet 40are guided by guiding section 19 of strut l6 and by power member 34.Thus, all upstream and downstream travel of poppet 40 is guided at theexterior of its cup-shaped portion 42 by the guide 19 and at theinterior of its cup-shaped portion 42 by the power member 34. Therelatively great length of cup-shaped portion 42 as compared to thediameter of disc 41 assures smooth operation of poppet 40 as the poppetopens and closes the flow port defined by valve seat 15. This relativelygreat length also reduces the possibility of the poppet being in anygiven position. It should also be noted that spring 50 is substantiallyoutside of the normal flow of fluid through port 14.

As the temperature falls below the critical point and the upstreampressure falls below that pressure sufficient to overcome the biasingforce of spring 50 the poppet valve is once again urged to seat on valveseat 15 closing the flow port, thereby not allowing coolant fluid toflow through thermostatically controlled valve 10.

It will be understood of course that this embodiment of my invention hasbeen used for illustrative purposes only and that various modificationsand variations in the present invention may be affected withoutdeparting from the spirit and scope of the present invention as is setforth in the following claims.

I claim:

1. A waterline thermostat poppet valve comprising:

a transverse wallpiece having an annular valve seating surface defininga fluid flow port therethrough;

a thermal sensitive power unit having a power member reacting topredetermined ambient temperatures by variable extension therefrommounted to said wallpiece;

a poppet for cooperating with said surface to control the flow of fluidthrough said flow port, said poppet including a centrally locatedgenerally disc-shaped portion normally engaging said valve seatingsurface on the low pressure side thereon and a cup-shaped portion forslidably engaging the power member, said power member slidably engagingsaid poppet at the interior of said cup-shaped portion for unseatingmotion in response to a predetermined pressure independent of powermember extension; and

spring biasing means urging said poppet into said seated position onsaid valve seating surface.

2. The thermostat of claim 1 wherein said wallpiece includes a strutmounted to and extending in an upstream direction therefrom, said struthaving an undersurface facing in the generally downstream direction andsaid spring biasing means being interposed said undersurface and saidpoppet.

3. The thermostat of claim 2 wherein said strut has a guide meansgenerally aligned with said cup-shaped portion, said portion of thepoppet for guidingly directing the upstream and downstream movementsthereof.

1. A waterline thermostat poppet valve comprising: a transversewallpiece having an annular valve seating surface defining a fluid flowport therethrough; a thermal sensitive power unit having a power memberreacting to predetermined ambient temperatures by variable extensiontherefrom mounted to said wallpiece; a poppet for cooperating with saidsurface to control the flow of fluid through said flow port, said poppetincluding a centrally located generally disc-shaped portion normallyengaging said valve seating surface on the low pressure side thereof anda cup-shaped portion for slidably engaging the power member, said powermember slidably engaging said poppet at the interior of said cup-shapedportion for unseating motion in response to a predetermined pressureindependent of power member extension; and spring biasing means urgingsaid poppet into said seated position on said valve seating surface. 2.The thermostat of claim 1 wherein said wallpiece includes a strutmounted to and extending in an upstream direction therefrom, said struthaving an undersurface facing in the generally downstream direction andsaid spring biasing means being interposed said undersurface and saidpoppet.
 3. The thermostat of claim 2 wherein said strut has a guidemeans generally aligned with said cup-shaped portion, said portion ofthe poppet for guidingly directing the upstream and downstream movementsthereof.